I love the wrattens, I'm always looking to buy them from whoever is selling ( as long as they are not new) There isn't much to say about then other than high optical quality and their diversity of many different kinds of filters for black and white, they also set the standard for filter numbers, I know a filters characteristics by it's number so when I'm forced to use some off brand I find either it's kodak wratten number or compare it's transmission to the wrattens in nanometers , if such information is given anymore...